While the SAE says that odometer accuracy plus or minus 4% is within the realm of acceptability, Honda's setting a class action suit filed by owners of Accords bought between April 12, 2002 and November 7, 2006, by 5% after the vehicles' odos were found to be off as much as 3.75%, shorting the owners on their warranty coverage. Six million vehicles are affected by the settlement. Meanwhile, owners of Nissan Altimas are filing a similar suit, claiming they're being shorted by around 2.5%. – Davey G. Johnson